import random
from itertools import chain

def chain2(*args):
    for iter_obj in args:
        for i in iter_obj:
            yield i

def chain3(*args):
    for iter_obj in args:
        yield from iter_obj

chain_func=random.choice([chain,chain2,chain3])
c=chain_func({'one','two'},list('ace'))
for i in c:
    print(i)
